1.216 g of an organic compound was Kjeldahlised and the ammonia evolved was absorbed in 100 mL of 1-N H_(2)SO_(4). The remaining acid solution was made upto 500 mL by dilution with water. 20 mL of this diluted solution required 32 mL of N//10 NaOH solution for complete neutralisation. calculate the percentage of nitrogen in the compound.

1.216 g of an organic compound was Kjeldahlised and the ammonia evolve

1.	1.216 g of an organic compound was Kjeldahlised and the ammonia evolved was absorbed in 100 mL of 1-N H_(2)SO_(4). The remaining acid solution was made upto 500 mL by dilution with water. 20 mL of this diluted solution required 32 mL of N//10 NaOH solution for complete neutralisation. calculate the percentage of nitrogen in the compound.
Answer» Solution :Step I. Calculation of the normality of diluted `H_(2)SO_(4)` solution. Volume of `NaOH` solution = 32 mL Normality of `NaOH` solution `= N//10` Volume of the `H_(2)SO_(4)` solution `= 20` mL Normality of `H_(2)SO_(4)` solution can be calculated by applying normality equation `ubrace(N_(1)V_(1))_("Acid")= ubrace(N_(2)V_(2))_("Base")` `Nxx20=1/10xx32, N=32/(10xx20)` Step II. Calculation of the volume of unused `H_(2)SO_(4)` `ubrace(N_(1)V_(1))_("Conc. acid")= ubrace(N_(2)V_(2))_("Diluted acid")` `1xxV=(32xx500)/(10xx20)=80 mL`. Step III. Calculation of the volume of used `H_(2)SO_(4)` Total volume of `H_(2)SO_(4)` yaken = 100 mL Volume of `H_(2)SO_(4)` unused = 80 mL Volume of `H_(2)SO_(4)` used `100-80=20` mL. Step IV. Calculation of the percentage of nitrogen. Percentage of`(1.4xx"Normality of acid used"xx"Volume of acid used")/("Mass of the compound")` `=(1.4xx1xx20)/(1.216)=23.03 %`